
/**
*
*  Base64 encode / decode
*  http://www.webtoolkit.info/
*
**/

var Base64 = {

  // private property
  _keyStr: 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=',

  // public method for encoding
  encode: function (input, binary) {
    binary = (binary != null) ? binary : false
		var output = '';
    var chr1, chr2, chr3, enc1, enc2, enc3, enc4
		var i = 0

		if (!binary) {
      input = Base64._utf8_encode(input)
		}

    while (i < input.length) {
      chr1 = input.charCodeAt(i++)
			chr2 = input.charCodeAt(i++)
			chr3 = input.charCodeAt(i++)

			enc1 = chr1 >> 2
			enc2 = ((chr1 & 3) << 4) | (chr2 >> 4)
			enc3 = ((chr2 & 15) << 2) | (chr3 >> 6)
			enc4 = chr3 & 63

			if (isNaN(chr2)) {
        enc3 = enc4 = 64
			} else if (isNaN(chr3)) {
        enc4 = 64
			}

      output = output +
			this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
			this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4)

		}

    return output
	},

  // public method for decoding
  decode: function (input, binary) {
    binary = (binary != null) ? binary : false
		var output = '';
    var chr1, chr2, chr3
		var enc1, enc2, enc3, enc4
		var i = 0

		input = input.replace(/[^A-Za-z0-9\+\/\=]/g, '')

		while (i < input.length) {
      enc1 = this._keyStr.indexOf(input.charAt(i++))
			enc2 = this._keyStr.indexOf(input.charAt(i++))
			enc3 = this._keyStr.indexOf(input.charAt(i++))
			enc4 = this._keyStr.indexOf(input.charAt(i++))

			chr1 = (enc1 << 2) | (enc2 >> 4)
			chr2 = ((enc2 & 15) << 4) | (enc3 >> 2)
			chr3 = ((enc3 & 3) << 6) | enc4

			output = output + String.fromCharCode(chr1)

			if (enc3 != 64) {
        output = output + String.fromCharCode(chr2)
			}
      if (enc4 != 64) {
        output = output + String.fromCharCode(chr3)
			}
    }

    if (!binary) {
      output = Base64._utf8_decode(output)
		}

    return output

	},

  // private method for UTF-8 encoding
  _utf8_encode: function (string) {
    string = string.replace(/\r\n/g, '\n')
		var utftext = '';

    for (var n = 0; n < string.length; n++) {
      var c = string.charCodeAt(n)

			if (c < 128) {
        utftext += String.fromCharCode(c)
			} else if ((c > 127) && (c < 2048)) {
        utftext += String.fromCharCode((c >> 6) | 192)
				utftext += String.fromCharCode((c & 63) | 128)
			} else {
        utftext += String.fromCharCode((c >> 12) | 224)
				utftext += String.fromCharCode(((c >> 6) & 63) | 128)
				utftext += String.fromCharCode((c & 63) | 128)
			}
    }

    return utftext
	},

  // private method for UTF-8 decoding
  _utf8_decode: function (utftext) {
    var string = '';
    var i = 0
		var c = c1 = c2 = 0

		while (i < utftext.length) {
      c = utftext.charCodeAt(i)

			if (c < 128) {
        string += String.fromCharCode(c)
				i++
			} else if ((c > 191) && (c < 224)) {
        c2 = utftext.charCodeAt(i + 1)
				string += String.fromCharCode(((c & 31) << 6) | (c2 & 63))
				i += 2
			} else {
        c2 = utftext.charCodeAt(i + 1)
				c3 = utftext.charCodeAt(i + 2)
				string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63))
				i += 3
			}
    }

    return string
	}

}
